I don't really care how thin the iPad is, I care a lot more about weight. iPad Air is pretty light now, but I would love to see it even lighter. If that means thinner too, okay.
Of course, Apple needs to do this without losing battery life, which typically means more efficient chips that need less go juice. Battery tech is not advancing anywhere near as fast as I would like.
Anyway, when do we realistically expect to see this thing come out? October, or the same time as the new iPhone? There haven't been a whole lot of leaks, but then everyone seems so focused on the new iPhone and iWatch rumors, and chances are new iPad parts could be overlooked.